1. Field of the Invention
This invention relates to a process for the production of diamond powder without using any ultra-high pressure apparatus.
2. Description of the Prior Art
Synthesis of diamond has already been put to practical use by the use of an ultra-high pressure apparatus. This method consists in heating graphite and a metal such as Ni under an ultra-high pressure, e.g. several ten thousands atm to form diamond.
However, the price of such synthetic diamond powder is not much lower than that of natural diamond powder, since the ultra-high pressure apparatus itself consists of expensive and complicated equipment and needs a cemented carbide vessel for producing a high pressure, which is not only too expensive but also hard to be large-scaled. Furthermore, it has eagerly been desired to develop a method of producing diamond powder with a uniform particle size on a large scale, because classification of the fine powder used for polishing costs a great deal. On the other hand, a number of methods of synthesizing diamond from gaseous phase have been proposed, but in this case, diamond is obtained in the form of a film and there has been developed no effective method of obtaining diamond in the form of a powder.